Gang Saw GangProblemConstraintsGang Saw LayoutSaw Blade and Power RollersFeed RollersCircular Saw vs. Band SawBlade ConstraintsStandard BladesDiamond Tip BladesCarbide Tip BladesSaw Calculations (8 in.)Saw Calculations (10 in.)8 inch Carbide Tip w/8 teethShaft DesignShaft Design Cont’dShaft Selection Keyed vs. SplinedShaft PricesBearing SelectionMajor Motor ConstraintsAdvantages of the 15 hp motorDisadvantages of the 15 hp motorAdvantages of 2 x 5 hp motorsDisadvantages of 2 x 5 hp motorsAdvantages of 1 x 10 hp motorFeeder SystemFeeder ConsiderationsFeed RollersFeed Roller Power SupplyCost of Purchased RollersCost of Chain Feed SystemCost to Fabricate RollersBlade Spacing MechanismRequirements of Spacing MechanismAlternativesBabbitt Guide SystemConsideration of Babbitt Guide SystemConsideration of Set CollarsConsideration of Dual ArborsCompression Springs with Pneumatic ActuationCompression Springs with Rack and PinionCompression Springs with Rack and PinionCompression Springs with Rack and PinionSpring CalculationCalculation of Crank ForceCost AnalysisOSHA RegulationsGuardsPowerPowerMaintenanceMaintenanceQuestions?Gang Saw GangMohammad Jeelani Michael Knoblett Justin Owens Richard Thrift Jeremy Patterson Joseph Perry Barton Pate Mark Herndon Mike HudgensProblemProblem To design a reliable machine to cut various sizes of scrap wood into survey stakes of specific dimension To reduce labor  To maximize productionConstraintsConstraints $1500 Budget 10 x 10 square ft. area Compatibility with Indexer Design Size of lumberGang Saw LayoutGang Saw Layout Input conveyor with board alignment device Gang Saw Assembly Exit SlideSaw Blade and Power RollersSaw Blade and Power Rollers Blades Adjustable for 1 ½’’ or ¾’’ Cut 1 ½’’ Stakes for up to 12’’ Board Width ¾’’ Stakes for up to 6’’ Board Width Minimum Board Length 12’’Feed RollersFeed Rollers Spring Loaded Free Spinning Top Rollers Powered Knurled Bottom Rollers Powered Exit RollerCircular Saw vs. Band SawCircular Saw vs. Band Saw Low cost of equipment Low cost of maintaining them Low cost of saws High initial cost High cost of saws More susceptible to damage from hard materials embedded in woodBlade ConstraintsBlade ConstraintsAccording to Rip Saw Applications,we needed to meet a rim speed of 9000.Kerf for carbide tips-.15Teeth must clear wood8 inch blade for cutting 12 in. long piecesLarger the blade, the more maintenanceStandard BladesStandard BladesCheapWill not last longBlade tips break easyDiamond Tip BladesDiamond Tip Blades Mostly used for cutting steel.  Diamond is very hard, but edge is not as sharp. Higher cost Extremely fragile  There is a need for an increase of 15 to 30% in power consumption because of the increase in cutting pressure. Not using the right power,you can run into problems like:a. Premature edge wearb. chipped or broken teethCarbide Tip BladesCarbide Tip Blades Powder-like material in its raw state.  It is shaped by compressing it at high temperatures. Increasing the content of carbide, wear resistance increases but resistance to shock decreases. Harder and more resistant to corrosion. Much cheaper Lasts 20 times as long as the standard bladeSaw Calculations (8 in.)Saw Calculations (8 in.)R.P.M. = 3.8197 (Rim Speed) Saw Diameter= 3.8197 (9000 ft/m)8 inches= 4297.16Tooth Bite = Feed Rate (12)RPM (Teeth)= 16 ft/m(12)4297.16(8)=.0055Arbor RPM = 12 (Rim Speed)Saw Diameter(3.14)=12 (9000)8 in.(3.14)=4299.36Circumference =3.1416 (Diameter)=3.1416 (8 in.)=25.13HP per saw =D of C(Kerf)(FPM)(Factor)144= 1.5(.15)(16ft/m)(45)144=1.125Total HP= 1.125(7)=7.875Saw Calculations (10 in.)Saw Calculations (10 in.)R.P.M. = 3.8197 (Rim Speed) Saw Diameter= 3.8197 (9000 ft/m)10 inches= 3437.73Tooth Bite = Feed Rate (12)RPM (Teeth)= 16 ft/m(12)3437.73(10)=.0055Arbor RPM = 12 (Rim Speed)Saw Diameter(3.14)=12 (9000)10 in.(3.14)=3439.49Circumference =3.1416 (Diameter)=3.1416 (10 in.)=31.416HP per saw =D of C(Kerf)(FPM)(Factor)144= 1.5(.15)(16ft/m)(45)144=1.125Total HP= 1.125(7)=7.8758 inch Carbide Tip w/8 teeth8 inch Carbide Tip w/8 teeth Cost, most suitable for woodworking 12 inch boards would jam machine 8 teeth to carry load out of cutShaft DesignShaft DesignBending and Torsion1045 Steel-industry recommendedTorque on shaft from motorCalculated value of 0.632 inch diameter shaftShaft Design Cont’dShaft Design Cont’dIndustry experts recommend a diameter of 1 15/16 InchesCompare with calculated value¾ inch shaft selected based on calculations and bearing availabilityShaft Selection Keyed vs. SplinedShaft Selection Keyed vs. Splined KeyedCatalog item1045 Shafts AvailableSupplierCheap if purchasedEasier to machineEasy to replace SplinedNot catalog itemExpensive to purchaseDifficult to machineLong wait if shaft failsShaft PricesShaft Prices Keyed3/4 inch diameter24 inch lengthKeyway dim. of 3/16 IN.X 3/32 in.$ 30.00 Splined Have to be custom madeFinding machinistCustom job more expensiveBearing SelectionBearing SelectionSelf aligning for deflectionEccentric lock for one direction of rotationLoad and rpm ratingSupplier$30.00 per bearingCost of two - $60.00Major Motor ConstraintsMajor Motor ConstraintsSingle Phase MotorMaximum 15 hp MotorAdvantages of the 15 hp motorAdvantages of the 15 hp motor 15 hp motor results in a feed rate of 30 ft/min2.1 hp = (45)(.15in)X(1.5in) 144= 30 ft/min7 blades x 2.1 hp = 15 hpDisadvantages of the 15 hp motorDisadvantages of the 15 hp motorTEFC motor unavailableThe Cost of a 15 hp motor is $800Eliminates the fast feed rate of 30 ft/minThis eliminates the possibility of a 15 hpAdvantages of 2 x 5 hp motorsAdvantages of 2 x 5 hp motors Efficient according to hp calculations Hp per saw = 1.5(.15)(16)(45)144= 1.13 hp 7 blades x 1.13 hp = 8 hp 2 x 5 hp motors are equal to 1 x 10 hp motorDisadvantages of 2 x 5 hp motorsDisadvantages of 2 x 5 hp motors The Cost of 2 x 5 hp motors is $974 Hassle as far as one of the motors failing Motors have to be coupled together More space required for the two motorsAdvantages of 1 x 10 hp motorAdvantages of 1 x 10 hp motor The Cost is only $650